While performing an operation on an artery or a vein, such as angioplasty or implanting a stent within an artery, it is necessary for the surgeon to know the position and orientation of the tip of the catheter during the operation. The position and orientation can be determined in different ways, for example, by means of an electromagnetic sensor, ultrasonic sensor, or a marker attached to the catheter.
U.S. Pat. No. 6,353,379 issued to Busletta et al., and entitled “Magnetic Device Employing a Winding Structure Spanning Multiple Boards and Method of Manufacturing thereof”, is directed to a magnetic device which includes a magnetic core, a main circuit board, an overlay board and a plurality of conductors. The magnetic core includes a first portion and a second portion. The main circuit board and the overlay board include a winding structure. The main circuit board and the overlay include a first plurality of winding layers and a second plurality of winding layers, respectively. The conductors include a conductive via, a conductive post and a connector.
The overlay board is oriented parallel and proximate to the main circuit board. The first portion of the magnetic core is coupled to the main circuit board and the second portion of the magnetic core is coupled to the overlay board. The magnetic core is surface mounted to the main circuit board and to the overlay board. The conductive via are located on each of the main circuit board and the overlay board. The conductive post is located on the main circuit board and connects to the overlay board. The connector is coupled to an edge of the overlay board from the main circuit board. The conductors couple the first plurality of winding layers and the second plurality of winding layers together.
U.S. Pat. No. 5,850,682 issued to Ushiro and entitled “Method of Manufacturing Chip Type Common Mode Choke Coil”, is directed to a chip type common mode choke coil which includes a plurality of non-magnetic sheets, a first plurality of magnetic sheets and a second plurality of magnetic sheets. On each of the non-magnetic sheets a conductor line at a predetermined orientation is printed. The non-magnetic sheets are stacked on the top of one another and the ends of the conductor lines are alternately connected by through holes. In this manner, part of the conductor lines form a figure-eight-shaped primary coil and the rest of the conductor lines form a figure-eight-shaped secondary coil.
A laminate is formed by placing the non-magnetic sheets between the first magnetic sheets and the second magnetic sheets and joining them together under pressure. A first hole (i.e., a core arranging hole) is formed at the center of the figure-eight-shaped primary coil and a second hole is formed at another center of the figure-eight-shaped secondary coil. Each of the first hole and the second hole is filled with a magnetic paste.